Namid Observatory - Day 2

We started the day assembling the imaging train. Again, it was great to have the studios onsite, so we could do this in a clean, air conditioned environment

A good thing about our setup is that we don't have to be too worried about getting the backfocus exactly right. First, the scope has a fairly large critical focus zone, and second the Nightcrawler focuser extends up to 1". I.e. we only have to get it roughly right.

We mounted the whole imaging train on the back - everything is super stable!!!

Other things we did:

Delta-T box and program
Install the Delta-T box and control program (to control fans and heater)

Was pretty easy. The control program (PWI - Planewave Interface Software) keeps the mirrors above ambient temperature


But we couldn't figure out yet how to control the fans. There is a tab in the software for the fans, but I don't know how to connect it ...

Set site coordinates

We don't want these to be set automatically by the MSGPBox - they can vary slightly based on satellite acquisition. Instead we measured really carefully and :

Latitude: 31° 56' 49.00" N

Longitude: 108° 53' 51.00" W

Elevation: 1342.00 m 

Entered them in the mount and TSX.

Connect MGPBox

First, we noticed that we didn't have the RJ10 cable to connect the MGPBox to the mount to set temperature and pressure (for refraction correction). Will keep looking. A few years back it would have been easy to find one as every phone was using them. But these days ...

Front counterweights

The scope comes with small counterweights that go into the very front. They are fairly light, but being so far in the front make a huge difference

Guidescope

When we tried to put the guidescope on top, we realized that we didn't have the right bolts that fit into the rings AND sink into the saddle plates, so that we can mount them on top of the dovetail. Now the machine shop came REALLY handy. Richard extended the holes in the saddle plates just enough that we could use hex screws. Apart from that, this was straight forward.

But when we tried to put the ASI camera on it, we realized that we were missing and adapter!!! The scope (being designed for visual) only has a 1.25" eyepiece ending. The camera has a C- and T-thread. Need to figure out how to get this adapter ...

Balancing

Now, with the guidescope on top, we could balance the scope. Instead of moving the entire scope around we could use the guidescope for DEC balancing.

We balanced it manually and measured with the 10Micron software:

RA: 1.1% shaft-heavy

DEC: 1.7% front-heavy

Good enough for now...

Finally, we

• tied the cables down a little (don't want to do the final one until we are done).
• setup everything in TSX (equipment, filter config...)

... and with that, we were ready for some night work!!!

First, we wanted to do the polar alignment. Using any plate-solving based method is tricky if you have such a small field of view (< 1"). Both PemPro and PHD2 have a drift-based alignment. We can't use PHD2 as we don't have the guide camera mounted yet (FLI doesn't have an ASCOM driver!!!)

So, we tried to use PemPro. Installed, configured (tricky as neither the FLI camera nor the 10Micron mount were in the PemPro database). But we somehow couldn't get it working (didn't display any images that we took).

So we tried to make plate solving work. Usually All-Sky platesolving is easy to setup and very forgiving. But it wasn't. We could not get it to work - even when we were right next to the target star.

Then Richard realized that the small pieces on top of the guidescope were for manual targetting

<PHOTO of red circled guidescope image>.

With that, we could get a rough polar alignment using the 3 star alignment of the 10Micron mount. Tried again to use TSX plate solving - but no luck!!!

My hail mary was to use ModelCreator and ASTAP. I've never used ASTAP before, but everybody was raving about it (installation, robustness...) Installed both, tried ...

... and it just worked!!! Seriously!!! It solved all frames, no problem.

With that, we could finally do this:

1. created a model (using 40+ stars) using plate solving, measured polar alignment error: 5+'
2. do a rough alignment with the guidescope targetting circles
3. created another model with 40 stars measured error: 1'30" !!
4. Now, we could do the alignment with the camera (star was close enough to the camera view)
5. created another model: 35" - and then we let ModelCreator running to do a full model (90+ stars): 15"
6. one more, very accurate alignment
7. another full model: 7" !!!

And with that, we called it a night!!! Awesome!

... one thing we noticed was that the lights from the USB hub are REALLY bright (especially the blue ones). Need to cover them or turn them off completely.

Next: Day 3